To understand the huge fuss over Armando Galarraga, Jim Joyce and the "perfect game" that wasn't, thanks to umpire Joyce's blown call last night, you need to understand that baseball's "perfect game" is not only one of the most difficult feats in team sports but also one of the rarest.

A perfect game, for a pitcher, is literally that: not a single opposition batter reaches first base by any means, so that the minimum 27 batters are retired consecutively, without walks, errors or mishap. In 150-odd years of professional baseball in the US, prior to the start of this season, a perfect game had only been pitched 18 times in the major leagues. No pitcher has ever managed the feat twice. Considering that 2,400 Major League Baseball games are played every season, and around 400,000 in total, that's roughly one only every 20,000 games. That makes the extraordinary feat of taking all 10 wickets in a cricket innings or making a 147 break in snooker seem commonplace.

Until the 2010 season, it seems. Already this year, two perfect games have been pitched, by Roy Halladay of the Phillies and the unheralded Dallas Braden of Oakland – and that hasn't happened since 1880. And last night it looked like Armando Galarraga of Detroit was going to join them ... until Joyce blew it.

Galarraga had retired 26 batters and was looking for the third and final out of the ninth inning. The batter, Jason Donald, slapped a pitch to right, to the waiting fielder, who's throw beat him to first base and Donald was out, as the TV replays clearly show, by half a stride. To all except Joyce, who quickly and clearly declared Donald to be safe, and almost certainly robbed Galarraga of his place in history.

What happened next? Not quite what you might expect. On Wednesday night the Detroit players remonstrated, the fans booed in disgust and the nation agreed an injustice had been done. Joyce, after seeing the replays expressed his mortification at his error. And then today in Detroit, the Tigers and the Indians again came out to play, with Joyce umpiring as usual. Thomas Boswell, the doyen of American baseball writers, described the scene:

Fans of the recession-scalded Motor City brought themselves to cheer for a man who admitted his mistake, which had denied one of their own a perfect game, a feat accomplished just 20 times since 1858. And, everywhere, observers shook their heads that a thing that was so sad and screwed up late Wednesday night could, simply by good will and compassion, be turned into something sparklingly fresh, unexpectedly strong and best-of-baseball by Thursday afternoon.

It was James Joyce – the novelist, not the baseball umpire – who wrote in Ulysses: "A man of genius makes no mistakes. His errors are volitional and are the portals of discovery." James Joyce III, the umpire, wouldn't agree about the voluntary nature of mistakes but perhaps he would for the "portal of discovery". The New York Times reported from today's game:

As the game began, Joyce's fellow umpires surrounded him in support, while members of the Tigers regularly stopped by home plate as they moved to their positions in the field. Some patted his arm and spoke a few words.

Still emotional afterward, Joyce said the game had been "the best 3 hours and 20 minutes in the last 24."

"I don't want to make it sappy and say it was love," Joyce said. "But the support I got was just ... love."